1. Field of the Invention
The present invention relates to a waterproof control unit, such as an in-vehicle electronic control unit installed in an engine room.
2. Description of the Related Art
Among conventional waterproof control units, one example waterproof control unit that is widely used includes: an enclosure formed of a base and a cover as described below; a circuit board hermetically contained in the enclosure with circuit components and a plurality of contact terminals for external connection mounted thereon and a resin-molded connector housing positioned and fixed; and waterproof seal material that fills first to third seal gaps in order to expose outside the enclosure the edge face of the connector housing with the plurality of contact terminals provided therethrough, the first seal gap being provided between the abutting faces of the connector housing and the cover, the second seal gap being provided between the abutting faces of the connector housing and the base, the third seal gap being provided between the abutting faces of the base and the cover.
Furthermore, a convexo-concave seal face method is widely used in which, as a waterproof seal face, for example, a convexo-concavo-convex thread is provided on the outer periphery of the cover, while a concavo-convexo-concave thread is provided on the outer periphery of the base, then the convexo-concave seal gap made by loosely fitting the convex thread on one side to the concave thread on the other side is filled with waterproof seal material.
In this case, the connector housing to be placed between the cover and the base needs to have a concavo-convexo-concave thread provided on the seal face of the cover side and a convexo-concavo-convex thread provided on the seal face of the base side, so two types of convexo-concave seal faces need to be provided in the connector housing.
A first advantage of such a convexo-concave seal face method is that, even with a small seal width, a long water exposure prevention distance (seal path) can be obtained. A second advantage is that, even when one of the convex thread wall surfaces abuts one of the concave thread wall surfaces to cause the film thickness of the waterproof seal material to be zero due to an assembly dimension error of the cover and the base, a gap between the other of the convex thread wall surfaces and the other of the concave thread wall surfaces is filled with the waterproof seal material, so at least one of the gaps between the wall surfaces is surely filled with a predetermined amount of the waterproof seal material.
On the other hand, a first disadvantage of the convexo-concave seal face method is that, as described above, two types of convexo-concave seal faces need to be provided in the connector housing, which causes the connector housing to be long-bodied and also increases the dimension of the plurality of contact terminals press-fit into the connector housing, so a measure to suppress increase in the electric resistance is required.
Furthermore, a second disadvantage of the convexo-concave seal face method is that, in order to ensure an adequate fitting depth of the convexo-concave faces, the apparent thickness dimension between the seal faces needs to be increased. Furthermore, a third disadvantage is that, for example, with a sheet metal cover, it is difficult to make a fine convexo-concave face that is narrow and deep, and even with a resin-molded cover, it is almost impossible to make a convexo-concave face that is excessively narrow and deep from the viewpoint of mold life, so an expected compact size is limited, and an attempt to reduce the load on the mold increases the body length of the connector housing.
For example, referring to FIGS. 3 and 1 of Patent Document 1 “Electronic Apparatus” listed below, an electronic apparatus is shown in which a printed circuit board 40 with a connector mounted thereon is contained in an enclosure and an internal space of the enclosure is waterproof, in which an upper case 20 (corresponding to the cover) and a lower case 30 (corresponding to the base) forming the enclosure include as a seal portion for abutting a seal material: an enclosure-side concave portion 35b formed on one of opening edge portions for connector; and an enclosure-side convex portion 25b formed on the other of the opening edge portions for connector, and in which apart opposed to the opening edge portions for connector on the surface of a housing 51 includes as an annular seal portion for abutting a seal material: a connector-side convex portion 54 to be inserted into the enclosure-side concave portion 35b with a seal material placed therein; and a connector-side concave portion 53 to be inserted into the enclosure-side convex portion 25b with a seal material placed therein, which are continuously formed.
Accordingly, the width of the connector-side concave portion 53 includes the width of the other two concave portions and the width of the connector-side convex portion 54, which corresponds to three times the width of the other concave portion. However, as shown in FIG. 1, the concave portions on both side of the connector-side convex portion 54 is in communication with the connector-side concave portion 53, so a waterproof seal material can be continuously applied as an advantage.
Furthermore, the seal faces between the housing 51 and the upper/lower cases 20, 30 are integrated with the outer face of a partition wall of the connector 50 with a connector terminal press-fit thereinto to limit the width of the convex portions and concave portions so that the total dimension of the press-fitting dimension of the connector terminal and the contacting dimension of the counter-side connector is suppressed to a minimum so as not to provide a long-dimensioned terminal.
Furthermore, referring to FIGS. 3 and 1 of Patent Document 2 “Electronic Control Apparatus” listed below, an electronic control apparatus 10 is shown in which a seal material 130 is placed between the opposing parts of the periphery of an upper case 50 (corresponding to the cover) and the periphery of a lower case 70 (corresponding to the base) forming an enclosure, between the opposing parts of a housing 111 of a connector 110 mounted on a circuit board 90 and the periphery of the upper case 50 and between the opposing parts of the housing 111 and the periphery of the lower case 70, and an internal space of the enclosure containing the circuit board 90 is waterproof, in which a convex portion for upper seal 57 provided on the upper case 50 and a concave portion for upper seal 119 provided on the housing 111 fit to each other, the convexo-concave seal faces of which are provided inside the partition wall of the housing 111, and in which a concave portion for lower seal 77 provided on the lower case 70 and a convex portion for lower seal 120a provided on the housing 111 fit to each other, the convexo-concave seal faces of which are provided outside the partition wall of the housing 111.
Thus, the seal faces between the housing 111 and the upper/lower cases 50, 70 are distributed between the inside face and the outside face of the partition wall of the connector 110 with a connector terminal press-fit thereinto to limit the width of the convex portions and concave portions so that the total dimension of the press-fitting dimension of the connector terminal and the contacting dimension of the counter-side connector is suppressed to a minimum so as not to provide a long-dimensioned terminal.
Furthermore, referring to FIG. 3 of Patent Document 3 “Board Container Enclosure For In-vehicle Electronic Apparatus” listed below, a circuit board 40 is hermetically contained in a metal enclosure formed of a metal base 30 and a metal cover 20; a concave thread provided on the cover 20 and a convex thread provided on a connector housing 41 fit to each other, the convexo-concave seal faces of which are provided inside the partition wall of the connector housing 41; and a convex thread provided on the base 30 and a concave thread provided on the connector housing 41 fit to each other, the convexo-concave seal faces of which are also provided inside the partition wall of the connector housing 41.
However, the two types of convexo-concave seal faces provided on the connector housing 41 are placed deviated from each other, which causes the connector housing to be long-bodied.
As described above, in any case of the Patent Documents 1 to 3, the two types of convexo-concave seal faces need to be provided on the connector housing, which causes the connector housing to be long-bodied, in which the two types of convexo-concave seal faces need to be in communication with each other via a waterproof seal material, which are connected to a common pool in the cases of the Patent Documents 2 and 3.
[Patent Document 1] JP-A-2009-070855
[Patent Document 2] JP-A-2009-123558
[Patent Document 3] JP-A-2013-004611
The “Electronic Apparatus” according to the Patent Document 1 is provided in the housing 51, in which the convexo-concavo-convex seal face centering the connector-side concave portion 53 fitting to the enclosure-side convex portion 25b of the upper case 20 and the concavo-convexo-concave seal face centering the connector-side convex portion 54 fitting to the enclosure-side concave portion 35b of the lower case 30 cross and join together in the middle portion of the side face of the housing 51.
Accordingly, the connector opening portion of the upper case 20 and the connector opening portion of the lower case 30 are rising up to the middle portion of the side face of the connector, so a problem is that the total weight is large when, for example, the lower case 30 is made of aluminum die-cast and the upper case 20 is resin-molded.
The “Electronic Control Apparatus” according to the Patent Document 2 is provided in the housing 111, in which the convexo-concavo-convex seal face centering the concave portion for upper seal 119 fitting to the convex portion for upper seal 57 of the upper case 50 and the concavo-convexo-concave seal face centering the convex portion for lower seal 120a fitting to the concave portion for lower seal 77 of the lower case 70 are placed with the partition wall of the housing 111 in between.
Accordingly, the lower case 70 is extended beyond the partition wall of the housing 111, so a problem is that the total weight is large when, for example, the lower case 70 is made of aluminum die-cast and the upper case 50 is resin-molded.
The “Board Container Enclosure For In-vehicle Electronic Apparatus” according to the Patent Document 3 is provided in the connector housing 41, in which the concavo-convexo-concave seal face centering the connector housing-side convex thread fitting to the concave thread of the cover 20 and the convexo-concavo-convex seal face centering the connector housing-side concave thread fitting to the convex thread of the base 30 cross and join together in both edge portions in longitudinal direction of the connector housing 41 in the base 30.
Accordingly, a problem is that a long-bodied connector is provided. Another problem is that the cover 20 and the base 30 are made of a sheet metal, and the convexo-concave seal face pressed corrugated is shallow and wide, so the connector is further long-bodied and the connector pin is elongated, which increases the cost. Another problem is that, even when the cover is resin-molded and the base is made of aluminum die-cast, for a narrow and deep convexo-concave seal face, making a mold is difficult, demolding is difficult, and also mold life is short. This also applies to the cases of the Patent Documents 1 and 2.